For my own work I'm planning to do it this way: - Incorporate the -3 check with the usual unit tests and pylint run for checking a module as I work on it. - S

For my own work I'm planning to do it this way: - Incorporate the -3 check with the usual unit tests and pylint run for checking a module as I work on it. - Stay compatible with Py2.X and these additional checks, and when curiousity strikes, run 2to3 to see what happens. The codebase will probably grow some different idioms needed to clear up 2-vs-3 ambiguities; that's OK. I'll learn how to avoid these ambiguities as I go. - When the community seems to be ready for 3.X (in particular, when Debian switches), most of the migration work will have already been done and the 2to3 script should work more or less perfectly for creating a new 3.X branch.